ABSTRACT:
Medical crowdfunding depends on visible donation signals that help prospective donors assess campaign credibility. Yet platform design choices that allow donors to remain anonymous may weaken these signals. Drawing on signaling theory and information cue theory, we conceptualize donor anonymity as a double-edged sword: it protects donor privacy and intrinsic giving motives, but it also reduces the diagnosticity of donation histories for subsequent donors. Using donation-level data from GoFundMe medical campaigns, we find that each anonymous donation among the three most recent donations reduces subsequent donation amounts by approximately 5.5 percent, net of campaign heterogeneity. We term this pattern the anonymity penalty effect. This effect is moderated by signal substitutes and campaign stage. Large cumulative anonymous donations and large individual anonymous donations attenuate the penalty, suggesting that donation size can partially compensate for missing identity cues. By contrast, the penalty intensifies in late-stage campaigns, when donors appear to rely more heavily on visible identity signals as campaigns approach their funding goals. A randomized controlled experiment provides evidence consistent with the archival findings and identifies reduced signal diagnosticity as the mechanism underlying the anonymity penalty effect. Theoretically, this study extends signaling theory and information cue theory to medical crowdfunding by showing that donor identity operates as a diagnostic legitimacy cue in settings without institutional verification, identifying anonymity as a platform-generated signal externality, and revealing how identity, donation size, and campaign stage interact in shaping donor behavior. Practically, the findings suggest that crowdfunding platforms should design anonymity options and recent-donation displays jointly, balancing donor privacy with the need to preserve signal diagnosticity through features that contextualize anonymous donations, highlight large anonymous contributions, or otherwise compensate for withheld donor identities.
Key words and phrases: Crowdfunding, charitable crowdfunding, medical crowdfunding, donor anonymity, donation size, signal diagnosticity, signaling theory, information cue theory, platform design